1. Field of the Invention
Motor vehicles special driving device steered by walking attendant who steerably controls steerable wheel; handle movement controls vehicle drive.
Wheeled land vehicles: articulated vehicles being of the pallet truck type; and further having vertically adjustable drive wheels attached to the platform.
2. Description of the Prior Art
Trailer maneuvering devices are well known in the art. They are used to transport within a confined area a travel trailer, a fifth wheel type of trailer, or the big rig semi-trailers used by commercial trucking companies. The typical trailer maneuvering device can be gasoline powered, hydraulically powered, or manually operable. They all have in common a support platform, a set of wheels attached to the platform to allow the device to roll on the pavement, and a front steering wheel which can be guided by the operator by some type of steering mechanism such as a lever or handle. The typical platform has a hitch ball assembly so that it can be hitched up with the tongue and sprocket, which is the front towing arm extending from the conventional travel trailer, in order to maneuver the trailer. The trailer maneuvering devices can either pull (tow) the trailer or push the trailer to maneuver and park, or dock the trailer at whatever destination is desired by the operator. In the self-contained and self-propelled trailer maneuvering devices, there is usually a gasoline powered engine, which in turn runs an hydraulic pump for providing hydraulic pressure to the lift mechanism and to provide power to the drive wheels of the trailer maneuvering device.
Thurman, U.S. Pat. No. 4,629,020, shows an example of a trailer maneuvering device for moving large semi-trailer tractor units and which has a scissors-like hydraulic ram for lifting a bearing sleeve trunnion for connection to a fifth wheel type of connection as found in large commercial vehicles.
Sheilds, U.S. Pat. No. 3,942,823, illustrates an example of a gasoline powered trailer maneuvering device which is manually steerable.
Soyk, U.S. Pat. No. 4,629,391, illustrates an example of a power lifter for moving a disabled vehicle from one location to another. It utilizes an hydraulic cylinder which has a telescoping mast. The cylinder is powered by an hydraulic pump, which is in turn rotated by an electric motor.